#define _CRT_SECURE_NO_WARNINGS 1

#include<stdio.h>

int fib(int n)
{
	if (n <= 2)
	
		return 1;
	
	else

		return fib(n - 1) + fib(n - 2);
}

int main()
{
	int i;
	while (scanf("%d", &i))
	{
		printf("%d\n", fib(i));
	}
	return 0;
}
